This invention relates to non-aging epoxy compatible sizes.
In one of its more specific aspects, this invention relates to non-aging epoxy compatible sizes having improved storage properties.
It is conventional in the glass fiber producing industry to apply a size to the surface of the glass to improve its handling and processing characteristics. One frequently employed size is an epoxy compatible size, that is, a size designed to be compatible with epoxy resins with which the glass fibers are employed.
One of the more frequently employed sizes of this kind is a solvent-based size comprising diacetone alcohol. However, this size imparts strength to the glass upon application thereto only if kept refrigerated while in storage.
There has now been developed a size which is epoxy compatible and which does not require refrigerated storage to prevent loss of strength-imparting qualities when applied to the glass fibers.
The size can be employed with both E-glass (optimum characteristics for electrical applications) and S-glass (high strength glass) as well as glass employed in filament winding and all other glass strands. When so applied, the size gives fast and complete wet-out, imparts high shear and tensile strengths in epoxy composites, is low cost and can be applied from an aqueous media. The size is mixed and applied in the conventional manner.